Celsius is easy to work out, just remember 0C is the point of freezing water and 100C the point of boiling water. So 0C is cold 10C is mild 20C is warm 30C is hot and 40C is bloody dam hot. It's the opposite way when cold only it's minus so -10 C is pretty dam cold. It was - 11C here one winter years ago. I'm surprised you don't know the Celsius scale Sticks.
Here's a link to a little weather station you can have in the system tray on your computer if anyones interested. It tells you the temp in C and F and weather anywhere in the world. You can set it for your home town.
http://getweathercast.com/